Rice Protein Peptides Alleviate Dextran Sulfate Sodium-Induced Colitis via the Keap1–Nrf2 Signaling Pathway and Regulating Gut Microbiota

Abstract

Inflammatory bowel disease (IBD), with increasing incidence, causes a range of gastrointestinal symptoms and brings distress and impact on the health and lives of patients. The aim of this study was to explore the protective effects of industrially produced rice protein peptides (RPP) on dextran sulfate sodium (DSS)-induced acute colitis in mice and the potential mechanisms. The results showed that RPP treatment alleviated the symptoms of colitis in mice, including weight loss, colon shortening, and injury, decreased the level of disease activity index (DAI), regulated the balance of inflammatory factors and oxidation, activated Kelch-like ECH-associating protein 1 (Keap1)-nuclear factor E2-related factor 2 (Nrf2) signaling pathway, regulated the expression of related antioxidant proteases, and promoted the expression of intestinal tight junction proteins. In addition, RPP maintained intestinal mucosal barrier function and alleviated acute colitis caused by DSS treatment in mice by increasing the value of F/B, increasing the relative abundance of beneficial bacteria such as Akkermansia, and regulating the level of short-chain fatty acids. In conclusion, RPP alleviated colitis symptoms through the Keap1–Nrf2 signaling pathway and regulating gut microbiota, which had the potential as dietary supplements or functional foods.

Neuroprotective Effects of a Novel Tetrapeptide SGGY from Walnut against H2O2-Stimulated Oxidative Stress in SH-SY5Y Cells: Possible Involved JNK, p38 and Nrf2 Signaling Pathways

“…In this study, as shown in Figure 5 , SGGY significantly promoted the nuclear translations of Nrf2 in SH-SY5Y cells, indicating that the protective effects of SGGY on SH-SY5Y cells were related to the activation of Nrf2. This result was consistent with the previous report that peptides could activate the Nrf2-Keap1 signaling pathway [ 39 ]. A recent study also found that a strong interaction existed between walnut-derived peptides and Keap1 by the method of molecular docking [ 26 ].…”

Oxidative Stress, Inflammation, Gut Dysbiosis: What Can Polyphenols Do in Inflammatory Bowel Disease?

“…In addition, the metabolites of polyphenols in the colon segment catabolized by microbiota results in increased anti-inflammatory activity [ 74 , 75 ]. A great number of studies have shown that polyphenolic compounds positively regulate antioxidant signaling pathways, such as Nrf2 [ 76 , 77 ], to intensify the intestinal mucosal barrier, which is also beneficial for the homeostasis of the gut microbiota [ 78 , 79 , 80 ]. Intriguingly, some microbial phenolic metabolites, which are generated through the interaction of undigested phenolic compounds and the microbiota found in the colon, have greater relevance and bioavailability than their precursors [ 12 ].…”

Potential Benefits of Egg White Proteins and Their Derived Peptides in the Regulation of the Intestinal Barrier and Gut Microbiota: A Comprehensive Review

“…In addition, intestinal disorders can lead to metabolic diseases, including cardiovascular diseases and cancer . Therefore, repairing the intestinal barrier and regulating gut microbiota are key targets for treating and preventing gastrointestinal inflammation and metabolic diseases. , The European Society for Clinical Nutrition and Metabolism suggested that adults with inflammatory bowel disease (IBD) should increase their protein intake to 1.2–1.5 g/kg body weight/day, compared to that consumed by the healthy population (0.83 g/kg body weight/day). , Furthermore, nutritional availability, especially that of proteins, is crucial during the illness treatment period . Therefore, the development of food-derived natural proteins as ingredients for nutritional supplements has wide application potential …”

“…13,14 Furthermore, nutritional availability, especially that of proteins, is crucial during the illness treatment period. 15 Therefore, the development of food-derived natural proteins as ingredients for nutritional supplements has wide application potential. 16 Eggs are the main high-quality proteins that are usually consumed in daily life, especially egg white proteins (EWP), which are currently one of the main sources of novel bioactive peptides.…”